in short, the CAGED method is just taking the open chords and barring them up higher frets. you probably do this all the time with A and E, but C G and D work well too. major or minor.
the pieces of each one kind of blend into each other (C and D are good example) and a good understanding of different voicings will do a lot to help you vary your rhythm playing, as well as helping with leads where you change with the chord (as opposed to just sticking with one scale).
CAGED is discussed further here: http://community.rukind.org/viewtopic.p ... ight=caged
You can also play lead over songs like this just be knowing the fretboard and leaning mostly on the notes that build each chord.